Re: [PATCH 23/36] driver core: bus: mark the struct bus_type for sysfs callbacks as constant

[Bjorn Helgaas]

On Mon, Mar 13, 2023 at 07:29:05PM +0100, Greg Kroah-Hartman wrote:
> struct bus_type should never be modified in a sysfs callback as there is
> nothing in the structure to modify, and frankly, the structure is almost
> never used in a sysfs callback, so mark it as constant to allow struct
> bus_type to be moved to read-only memory.
> 
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
> Cc: Alex Shi <alexs@xxxxxxxxxx>
> Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
> Cc: Alexandre Bounine <alex.bou9@xxxxxxxxx>
> Cc: Alison Schofield <alison.schofield@xxxxxxxxx>
> Cc: Ben Widawsky <bwidawsk@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxx>
> Cc: Harald Freudenberger <freude@xxxxxxxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Hu Haowen <src.res@xxxxxxxx>
> Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> Cc: Iwona Winiarska <iwona.winiarska@xxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
> Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: Stuart Yoder <stuyoder@xxxxxxxxx>
> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
> Cc: Wei Liu <wei.liu@xxxxxxxxxx>
> Cc: Yanteng Si <siyanteng@xxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>	# pci

> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index dd0d9d9bc509..ab32a91f287b 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -428,7 +428,7 @@ static ssize_t msi_bus_store(struct device *dev, struct device_attribute *attr,
>  }
>  static DEVICE_ATTR_RW(msi_bus);
>  
> -static ssize_t rescan_store(struct bus_type *bus, const char *buf, size_t count)
> +static ssize_t rescan_store(const struct bus_type *bus, const char *buf, size_t count)
>  {
>  	unsigned long val;
>  	struct pci_bus *b = NULL;
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7a67611dc5f4..45c3bb039f21 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6679,7 +6679,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
>  	}
>  }
>  
> -static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
> +static ssize_t resource_alignment_show(const struct bus_type *bus, char *buf)
>  {
>  	size_t count = 0;
>  
> @@ -6691,7 +6691,7 @@ static ssize_t resource_alignment_show(struct bus_type *bus, char *buf)
>  	return count;
>  }
>  
> -static ssize_t resource_alignment_store(struct bus_type *bus,
> +static ssize_t resource_alignment_store(const struct bus_type *bus,
>  					const char *buf, size_t count)
>  {
>  	char *param, *old, *end;